Copper-Catalyzed Multicomponent Coupling Reaction of Primary Aromatic Amines, Rongalite, and Alkynes: Access to N-Aryl Propargylamines.

In this work, a practical copper-catalyzed multicomponent coupling reaction of primary aromatic amines, rongalite, and alkynes for the direct synthesis of N-aryl propargylamines has been developed. This method could overcome the substrate limitation in A3 coupling reactions of primary aromatic amines, formaldehyde, and alkynes. Mechanistic studies revealed that rongalite acts as not only the active C1 unit but also the accelerator to activate the in situ-generated N-arylmethanimines for the coupling reaction with alkynes. This coupling reaction is highly efficient and features a broad substrate scope, as well as utility with scale-up synthesis and converting the corresponding product N-aryl propargylamines into useful heterocyclic skeletons.

Rongalite/iodine-mediated C(sp3)-H bond oximation and thiomethylation reaction of methyl ketones using copper nitrate as the [NO] reagent: synthesis of thiohydroximic acids.

In this work, a highly efficient rongalite/iodine-mediated oxime formation reaction for the preparation of thiohydroximic acids from methyl ketones by employing copper nitrate as the [NO] reagent has been developed. Notably, copper nitrate participated as both a catalyst and the mild oximation reagent in the transformation. This reaction is highly efficient and facile, with a broad substrate scope, especially for fused ring skeleton substrates, heterocyclic skeleton substrates, and acetyl-substituted natural products. Mechanistic studies revealed that copper nitrate might be converted into a NO2 radical or the NO2 radical dimeric forms as an ion-pair equivalent to participate in the transformation.

Post translational modifications of connexin 43 in ventricular arrhythmias after myocardial infarction.

Ventricular arrhythmias are the leading cause of sudden cardiac death in patients after myocardial infarction (MI). Connexin43 (Cx43) is the most important gap junction channel-forming protein in cardiomyocytes. Dysfunction of Cx43 contributes to impaired myocardial conduction and the development of ventricular arrhythmias. Following an MI, Cx43 undergoes structural remodeling, including expression abnormalities, and redistribution. These alterations detrimentally affect intercellular communication and electrical conduction within the myocardium, thereby increasing the susceptibility to post-infarction ventricular arrhythmias. Emerging evidence suggests that post-translational modifications play essential roles in Cx43 regulation after MI. Therefore, Cx43-targeted management has the potential to be a promising protective strategy for the prevention and treatment of post infarction ventricular arrhythmias. In this article, we primarily reviewed the regulatory mechanisms of Cx43 mediated post-translational modifications on post-infarction ventricular arrhythmias. Furthermore, Cx43-targeted therapy have also been discussed, providing insights into an innovative treatment strategy for ventricular arrhythmias after MI.

[Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats].

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

Overexpression of chloride channel-3 (ClC-3) is associated with human cervical carcinoma development and prognosis.

BACKGROUND: Cervical carcinoma is a major gynecological cancer and causes cancer-related deaths in worldwide, the latent pathogenesis and progress of cervical cancer is still under research. ClC-3 may be an important promoter for aggressive metastasis of malignant tumors. In this research, we explore the ClC-3 expression in cervical carcinoma and its underlying clinical significance, trying to illuminate ClC-3 probable function in the neoplasm malignant behavior, development and prognosis. METHODS: Paraffin-embedded cervical (n = 168) and lymph node (n = 100) tissue specimens were analysed by immunohistochemistry. Fresh human cervical tissue specimens (n = 165) and four human cervical cell lines were tested for ClC-3 mRNA and protein expression levels by quantitative real-time PCR and western blotting. The relationship between the expression levels of ClC-3, the pathological characteristics of the carcinoma, and the clinical prognosis were statistically analysed. RESULTS: In normal and precancerous (LSIL, HSIL) cervical tissues as well as cervical carcinoma tissues, both ClC-3 mRNA and protein expression levels increased significantly (p < 0.05). The expression level of ClC-3 was closely-related to the histological differentiation (p = 0.029), tumour staging (p = 0.016), tumour size (p = 0.039), vascular invasion (p = 0.045), interstitial infiltration depth (p = 0.012), lymphatic metastasis (p = 0.036), and HPV infection (p = 0.022). In an in vitro experiment, ClC-3 mRNA and protein were found to be overexpressed both in the HeLa and SiHa cell lines, but low expression levels were detected in the C-33A and H8 cell lines (p < 0.05). Furthermore, the high expression levels of ClC-3 was significantly correlated to poor survival in cervical carcinoma patients (Log-rank test, p = 0.046). CONCLUSIONS: These data suggest that overexpression of ClC-3 is closely associated with human cervical carcinoma progression and poor prognosis; this suggests that ClC-3 may function as a patent tumour biomarker and a latent therapeutic target for cervical carcinoma patients.

MicroRNA-224 inhibition prevents progression of cervical carcinoma by targeting PTX3.

Cervical carcinoma is known as one of the most lethal and common conditions in women worldwide. Increasing evidence shows that microRNAs (miRs) may be involved in the pathogenesis of cervical carcinoma. This study investigates the correlation between expression of miR-224 in peripheral blood mononuclear cells and both diagnosis and prognosis of cervical carcinoma to clarify the effect miR-224 has on the biological behaviors of the subjected cervical carcinoma cells. Initially, 132 patients diagnosed with cervical carcinoma and 120 healthy subjects were recruited. Peripheral blood expression of miR-224 and PTX3 was detected. A telephone follow-up was performed every 3 months after treatment. The diagnostic value of miR-224 in cervical carcinoma was analyzed using the Receiver Operating Characteristic curve. The effects of both miR-224 and PTX3 on cell proliferation, migration, and invasion were evaluated with an intervention of miR-224 ectopic expression or depletion and PTX3 silencing. The bioinformatics prediction website and dual-luciferase reporter assay revealed PTX3 to be a target gene for miR-224. Moreover, miR-224 was detected as over-expressed, but PTX3 was under-expressed in cervical carcinoma. Additionally, as a diagnostic biomarker, a high miR-224 expression was closely linked with the progression of cervical carcinoma. Both miR-224 overexpression and PTX3 silencing promoted cell proliferation, migration, and invasion, whereas, the aforementioned properties were depressed when miR-224 was inhibited. Altogether, the miR-224 overexpression may be a biological indicator in predicting the progression of cervical carcinoma. Thus, miR-224 inhibition may significantly prevent cervical carcinoma progression by targeting the PTX3 gene.

The RopGEF2-ROP7/ROP2 Pathway Activated by phyB Suppresses Red Light-Induced Stomatal Opening.

Circadian rhythm of stomatal aperture is mainly regulated by light/darkness. Blue and red light induce stomatal opening through different mechanisms that are mediated by special receptors. ROP2, a member of Rho GTPase family in Arabidopsis (Arabidopsisthaliana), has been found to negatively regulate light-induced stomatal opening. However, the upstream guanine nucleotide exchange factor (GEF) RopGEFs have not been revealed, and it is unclear which photoreceptor is required for the action of RopGEFs-ROPs. Here, we showed that RopGEF2 acted as a negative regulator in phytochrome B (phyB)-mediated red light-induced stomatal opening. Meanwhile, ROP7, another member of ROP family, acting redundantly with ROP2, was regulated by RopGEF2 in this process. RopGEF2 interacted with ROP7 and ROP2 and enhanced their intrinsic nucleotide exchange rates. Furthermore, the direct interactions between phyB and RopGEF2 were detected in vitro and in plants, and phyB enhanced the GEF activity of RopGEF2 toward both ROP7 and ROP2 under light. In addition, RopGEF4 functioned redundantly with RopGEF2 in red light-induced stomatal opening by activating both ROP7 and ROP2, and RopGEF2/RopGEF4 acted genetically downstream of phyB; however, the GEF activity of RopGEF4 was not directly enhanced by phyB. These results revealed that red light-activated phyB enhances the GEF activities of RopGEF2 and RopGEF4 directly or indirectly, and then activate both ROP7 and ROP2 in guard cells. The negative mechanism triggered by phyB prevents the excessive stomatal opening under red light.

Pine bark extracts: nutraceutical, pharmacological, and toxicological evaluation.

Proanthocyanidins are among the most abundant constituents in pine bark extracts (PBEs). This review summarizes medical research on PBEs from Pinus pinaster, Pinus radiata, Pinus massoniana, and other less well characterized species. The precise mechanisms of the important physiologic functions of PBE components remain to be elucidated, but there is evidently great potential for the identification and development of novel antioxidant, anti-inflammatory, cardiovascular, neuroprotective, and anticancer medicines. Although toxicological data for PBEs are limited, no serious adverse effects have been reported. PBEs, therefore, may have potential as nutraceuticals and pharmaceuticals and should be safe for use as food ingredients.

The Beneficial Effects of Electro-acupuncture at PC6 (Neiguan-point) of Gene and Protein Expressions of Classical Inward-rectifier Potassium Channels in Myocardial Ischemic Rats.

This study is aim to investigate the effect of electro-acupuncture at PC6 (Neiguan-point) on the gene and protein expressions of classical inward-rectifier potassium channels (Kir) in myocardial ischemia (MI) rats induced by isoproterenol (ISO). With ten for each one, 50 rats were divided into 5 groups which were control group, MI group, PC6 group, LU7 (Lieque-point) group and non-acupoint group. The control group was injected normal saline solution (85 mg/kg), the other groups were injected ISO (85 mg/kg). All the rats were injected once daily for two days and recorded electrocardiograms (ECGs) after every injection. Electro-acupuncture (EA) was operated at PC6, LU7 and non-acupoint respectively in the rats of PC6 group, LU7 group and non-acupoint group after twice injections. EA was performed to these three groups with disperse-dense wave (4-20 Hz), pulse amplitude of 14V, 20 mins a day remaining 7 days. The gene and protein expressions of Kir2.1, Kir2.2 and Kir2.3 were analyzed by Western Immunoblotting Technology (Western Blot) and Real-time Fluorescence Quantitative Polymerase Chain Reaction (RT-PCR). But it is regrettable that we did not detect meaningful gene and protein expressions Kir2.3, and the expressions of Kir2.1 and Kir2.2 in MI induced groups were lower [The gene and protein decreased 39.4 ± 27.3% and 38.7 ± 17.1% respectively.] than control group (P < 0.05). Compared with MI group, the results of PC6 group and LU7 group increased [PC6 group: the gene and protein increased 42.9 25.0% and 42.2 ± 10.0% respectively. LU7 group: the gene and protein increased 23.8 ± 50.1% and 21.1 ± 32.5% respectively.] obviously (P < 0.05) after EA, furthermore the expressions of PC6 group were higher [The gene and protein increased 15.4 ± 16.7% and 17.3 ± 60% respectively.] than LU7 group (P < 0.05). The results show that PC6 has a better positive effect than LU7 on MI rats, and the mechanism is probably that EA at PC6 can significantly increase the gene and protein expressions of Kir2.1 and Kir2.2.

Lacking chloroplasts in guard cells of crumpled leaf attenuates stomatal opening: both guard cell chloroplasts and mesophyll contribute to guard cell ATP levels.

Controversies regarding the function of guard cell chloroplasts and the contribution of mesophyll in stomatal movements have persisted for several decades. Here, by comparing the stomatal opening of guard cells with (crl-ch) or without chloroplasts (crl-no ch) in one epidermis of crl (crumpled leaf) mutant in Arabidopsis, we showed that stomatal apertures of crl-no ch were approximately 65-70% those of crl-ch and approximately 50-60% those of wild type. The weakened stomatal opening in crl-no ch could be partially restored by imposing lower extracellular pH. Correspondingly, the external pH changes and K(+) accumulations following fusicoccin (FC) treatment were greatly reduced in the guard cells of crl-no ch compared with crl-ch and wild type. Determination of the relative ATP levels in individual cells showed that crl-no ch guard cells contained considerably lower levels of ATP than did crl-ch and wild type after 2 h of white light illumination. In addition, guard cell ATP levels were lower in the epidermis than in leaves, which is consistent with the observed weaker stomatal opening response to white light in the epidermis than in leaves. These results provide evidence that both guard cell chloroplasts and mesophyll contribute to the ATP source for H(+) extrusion by guard cells.